You can use Include to separate positive from negative with the output from Isosurface. Pass the output of the negative Include to Sample and then to Glyph with type "needle". This isn't exactly a line, although you could pass it a line made with Construct. You'll need to play a bit with size/scale, as well as the number of Samples, etc. For dotted lines, you could you ShowPositions as output from Include or Isosurface (but they will be single pixels). Alternatively, you could use a "circle" glyph. When you have things the way you like, you could package them in a macro.
I recall that Chris Pelkie had a trick for dashed contour lines from perhaps a decade ago. I don't remember the details, however... "George F. Carnevale" <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 08/21/2001 01:23:20 PM Please respond to [email protected] Sent by: [EMAIL PROTECTED] To: [email protected] cc: Subject: Hi, Could someone tell me how to change the style of selected lines in a contour plot to dashed, dotted, chain-dashed etc. I would like to make a simple two-dimensional contour plot with dashed lines for negative values, and solid lines for positive values, with no color (just black on white). I can use dx to create contour plots with colored solid lines, but cannot figure out how to change the style of selected as is possible in NCAR graphics or gnuplot. Thanks. -george carnevale
